Anisotropic growth of a nickel trimer formed on a highly-stepped TiO2(1 1 0) surface

The structures of Ni clusters formed on a highly-stepped TiO2(1 1 0) surface were studied by polarization-dependent total reflection fluorescence X-ray absorption fine structure analysis. When 0.8 monolayers of Ni were deposited, three-dimensional Ni clusters with 1–2 nm diameters and heights less than 1 nm were formed. Conversely, when 0.07 monolayers of Ni were deposited, an anisotropic Ni trimer with a Ni–Ni distance of 0.260 nm was created at the [0 0 1] step. We revealed that the surface modification to enhance the metal–anion interaction can control the deposited metal structure.